Homer w



No. 623,989. Patented May 2, I899;

H. w. consa.

ELECTRIC MOTOR. (Application filed Sept. 9, 1898.)

QNo Model.)

Inventor,

Homer W Curse;

UNTTED STATES PATENT EEicE.

HOMER \V. ()ORSE, OF MELROSE, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TOTHOYIAS S'. SIMONDS, OF SAME PLACE.

ELECTRIC MOTOR.

SPECIFICATION forming part of Letters Patent No. 628,989, dated May 2,1899.

Application fl fi September 9, 1898. Serial No. 690,558. (No model.)

1) (1/66 w/wnt it may concern:

.l3e it known that I, HOMER \V. CURSE, a citizen of the United States,residing at Melrose, in the county of Middlesex and State ofMassachust-itts, have invented a new and useful Electric Motor, of whichthe following is a full, clear, and exact description.

lllyinvention pertains to that class of electric motors in which thearmature is of the ring type; and it has to do with an improved meansfor cutting out successive sections of the armature-coils, and therebydiminishing the resistance and increasing the speed. My construction forthis purpose comprises, essentially, a series of contact-points for eacharmature-segment, each point connected with successive sections of eachcoil and the whole revolving with the armature, and contactbrushesrevolving with the armature, but longitudinally movable with respectthereto, and adapted by such longitudinal adjustment to out in or cutout said successive sections of the armature-coils.

Referring to the drawings forming part of this specification, Figure 1is a plan view of an electric motor embodying my invention. Fig. 2 is alongitudinal section of the armature and allied portions,partlydiagrammatic; and Fig. 3 is a detail view of the contactpoints andcontact-brushes.

In Fig. l, A indicates the base-plate of a motor; a, the bearings risingtherefrom; B, the pole-pieces of the field-magnets; G, the armature;D,the commutator; D,thebrushes, and E the armature-shaft, revolving insaid bearings a.

Referring to Fig. 2, 0' indicates the core of one of the segments of thearmature 0, while 0 indicates the armature-windings of such segment.These windings may be of any requ'ired number and of diliferent sizes ofwire; but it is sufficient for my purpose to represent the windings tobe but six in number and of uniform wire throughout.

As shown in Fig. 2, there are as man y-contact-points f as there aresections in each armature-coil, and these points are connectedtherewith, as f with the section 0 through the wire 9, f with 0 throughg and so on.

These contact-points are supported by means of the long screws F,rigidly projecting from the disk F, whose elongated hub F is pinned uponthe shaft E; but said screws do not pass through said points, butbetween the dilterent series thereof in notches formed in their sides,as shown in Fig. 3. Asindicated, said points are insulated one from theother and from the screws F by suitable insulating material appliedbetween, the heavy black representing such insulation.

The contact-brushes comprise a head h, su pported at the extremity of aslender and resilient screw h, whose threaded end screws into the fiberdisk H, and said disk H is firmly clamped between the metal disks K andL, the hub K of one of which is slidable upon the hub F while they otheris slidable upon the shaft E and is provided with a flange L, by meansof which the adjusting-lever N is enabled to engage it and move itlongitudinally upon the shaft. Said lever is pivoted upon a boss a,rising from the bed-plate A.

As shown in Fig. 3, there is an equal num ber of contact-points f andspring-contacts h, and the contacting surfaces thereof are made sharplyand respectively concave and convex. The object of thus shaping thecontact-surfaces is twofold: first, to increase the surface in contactbetween each point, and, secondly, to insure that each spring-contactshall at all times remain in contact with its respective series ofcontact-points. \Vithout such eonformation it would be practicallyimpossible for said contacts to thus remain in accurate position, for afeather or spline upon the shaft for preventing the disk H from shiftingthereon would soon wear, or the pins or screws h might become bent, andthe spring-contacts would be completing the circuit with the wrong setof contact-points.

The terminal of the inner windings c is connected with its appropriatecommutator-seg ment, While the next following segment is joined throughthe wire 7L2 with the head lb of the proper spring-contact. Said wire7L2 is of course suitably insulated in its passage through the disk Fand is given sufficient slack to insure its non-injury when thespring-contacts are being shifted from one end of the contact-points tothe other.

The screws or .pins h are made slender and resilient not simply toinsure their contact with the contact-pointsf through the springpressureinherent in said pins, but I have found in practice that by making thesame somewhat slender the action of the centrifugal force upon the heads72 increases to a marked degree the contact-pressu re of the latter withthe points f.

In using this motor all that is needed to be done in order to vary itsspeed of rotation and increase or diminish its torque is to move thelever N, and thereby shift the position of the spring-contacts 72 to theappropriate contactpoints f.

lVhatI claim as my invention, and for which I desire Letters Patent, isas follows, to wit:

1. In a motor, the combination with the armature and commutator, of aseries of contact-points turning with said armature and electricallyconnected with respective sections of the armature-coils, and contactselectrically connected with said commutator and turning with saidarmature but longitudinally movable with respect thereto, wherebydifferent sections of the armature-coils can be cut in or cut out ofcircuit as desired, and the speed of the dynamo correspondingly varied.

2. In a motor, the combination with the armature and commutator, of aseries of contact-points for each segment of the armature andelectricallyconnected with respective sectious of the coils, a diskfixed upon the shaft of said armature and adapted to rigidly supportsaid contact points, a disk slidably mounted upon said shaft, and thespring-contacts held by said latter disk and insulated one from theother but electrically connected with the commu tator of thearmature,whereby different sections of the armature-coils can be cut inor cut out of circuit at will.

3. In a motor, the combination with the armature, its shaft andcommutator, of a series of contact-points for each segment of thearmature-coils electrically connected with respective sections of saidcoils, said points being held concentric with said shaft and having theV- shaped grooves parallel therewith, and the spring-contacts surfacedto fit said grooves and adapted to be moved in the direction of saidshaft and in electrical connection with the armature.

1-. In a motor, the combination with the armature, its shaft andcommutator, of the disk fixed upon said shaft, the screws tapped intosaid disk parallel with said shaft, the contact-points supported by saidscrews and elec- 'trically connected with different sections of thearmaturecoils, and the sliding springcontacts electrically connectedwith said commutator.

5. In a motor, the combination with the armature, its shaft andcommutator, of the disk fixed upon said shaft, the contact-points havingthe lateral grooves, the screws passing between said contact-points insaid grooves or notches, and tapped into said disk, suitable insulation,electric connection between said points and different sections of thearmaturecoils, and the sliding spring-contacts electrically connectedwith said commutator.

0. In a motor, the combination with the armature, its shaft andcommutator, of the contact-pointsheld concentric with said shaft andturning therewith and electrically connected with different seetions'ofthe armature-coils. the non conductive disk slidable on said shaft, andthe spring-contacts comprising the heads having the pins or screwstapped into said disk and electrically connected with said commutator.

7. In a motor, the combination with the armature, its shaft andcommutator, of the contact-points held concentric with said shaftaudturning therewith and electrically connected with different sections ofthe armature-coils, the non-conductive disk, the smaller metallic disksslidable on said shaft and clamping said non-conductive disk betweenthem, one there of having the flanged hub, the slender pins or screwstapped into said non-conductive disk and each carrying the head at itsouter end electrically connected with the proper segment of thecommutator, and means eugaging said flange for longitudinally adjustingsaid disks and allied parts upon said shaft, in orderto cut in or cutoutof circuitanyoue or more of the sections of the armature-coils and tothereby vary its speed at will.

In testimony that I claim the foregoing invention I have hereunto set myhand this 31st day of August, 1898.

HOMER \V. CURSE.

Witnesses:

A. 13. UPILUI, W. '1 Rron.

